Electrical testing device for attachment to flashlights



May 10, v1949. G. c. zAcHAE 2,469,910

ELECTRICAL TESTING DEVICE FOR l ATTACHMENT TO FLASHLIGHTS Filed Feb. 1:5, 194e ATTORNEY Patented May 10, 1949 UNITED STATES ELECTRICAL TESTING DEVICE FOR ATTACHMENT TO FLASHLIGHTS 3 Claims.

The present invention relates to an electrical testing device particularly adapted for use by electricians in testing wiring connections, lamp bulbs, fuses, and other electrical devices that are subject to failure.

In my Patent No. 2,292,730, issued August 1l, 1942, there is shown and described an electrical testing device of the above indicated character, which device is in the form of a convenient attachment which may be mounted on and forms part of a conventional portable flashlight, whereby the battery of the flashlight may be utilized for testing electrical circuits or other devices under examination. The particular ashlight attachment disclosed by my aforementioned patent is adapted for use in connection with any conventional ilashlight by the removal of the regular end cap, and the substitution therefor of a special cap providing connections whereby current from the battery maybe passed through circuits or devices under test.

According to the present invention, there is provided an improved electrical testing device for attachment to a conventional ilashlight, which incorporates not only certain features of my previously patented device, but also includes the provision of means for quickly determining the approximate electrical resistances of the circuits or devices under test. Briey stated, the improved device of the present invention consists of an electrical meter conveniently mounted on the cap that is attached to the portable flashlight, with the meter being so connected to the testing terminals of the attachment as to permit the resistances of the circuits or devices under test to be approximately determined as the testing device is used. In this Way, the electrician utilizing the device can conveniently make tests heretoiore impossible to make without the use of expensive meters and complicated testing equipment that is not readily portable.

The above and other advantageous features of the invention will hereinafter more fully appear from the following description considered in connection with the accompanying drawings, in which:

Fig. l is a View in perspective of a conventional flashlight on which is mounted an electrical testing device embodying the invention, with the meter mounting being open for use.

Fig. 2 is a perspective view similar to Fig. l, with the meter mounting closed.

Fig. 3 is a sectional view of the device shown in Fig. 1 removed from the flashlight, and on an enlarged scale.

(Cl. F- 183) Fig. 4 is a sectional view along the line l-4 of Fig. 5, looking in the direction of the arrows.

Fig. 5 is a diagram illustrating the use of the meter for testing an electrical circuit, with the testing cap being shown in plan.

Referring iirst to Figs. l and 2, there is shown for purposes of illustration a conventional ilashlight, comprising the usual tubular shell I, on one end of which is mounted a cap 2 containing the lens 3, with the associated reflector and bulb 5 being shown in dotted lines. A switch it is provided on the side of the shell i, by means of which the .bulb 5 may be illuminated from the usual battery 'i within the shell. The particular construction of the :Flashlight is conventional, and is of importance only to the extent that my irnproved testing device mounted on a special cap 8 may `be readily attached to the shell l in place of the usual cap that is employed to make an electrical connection between one end of the battery 'l and the metallic shell I.

The testing cap 3 is constructed in accordance with my aforesaid Patent No. 2,292,739, in that it provides a connection to the battery l and several testing terminals, later described. In accordance with the present invention, the cap 8 also provides a cover 9 of cup-like form, connected to the cap 8 by a hinge i@ and containing a small electrical meter Il. When the device is being used for testing, the cover 9 is turned back on its hinge Iii, as shown in Fig. 1, so that the meter i l may be readily observed. However, when the device is not in use, the cover t can be closed as shown in Fig. 2, so as to entirely conceal and protect the meter II until it is desired to again use the device for testing purposes.

As best shown in Fig. 3, the special testing cap 8 .is adapted to be secured to the shell I by any suitable means, such as threads (la, cooperating with the threaded end of the shell l, as in the usual flashlight construction. The entire `cap 8 is composed of electrical conducting material, and one end of the battery 'l within the shell I is normally connected to the cap 8 by a contact spring I2 mounted on the cap 8, so that closure of the switch 6 with the cap 8 `in place will cause illumination of the bulb 5, through its connection to the other end of the battery "l,

The contact spring I2 is of resilient material reversely bent, so that the yielding end portions 12a and l2b of the spring engage one end of the battery 'i and a circular disk portion i3 forming part of the cap 8. The spring I2 is mounted on the cap 8 by means of a stud I4 .passing through the disk portion I3 and insulated therefrom at i5.

Therefore, the stud I4 is always connected to one side of the battery 1, and can be used for testing pur-poses in a manner later described.

The end portion I2a of the spring I2 which normally bears on the cap 8 carries a disconnecting button I6 of insulating material, which eX- tends freely through an opening in the disk portion I3 and projects beyond the surface thereof. .`By exerting a pressure on the outerlend of said button I6, the end portion I'Za, of the spring can be flexed away from the cap 8, to thereby disconnect the entire shell I from the inside terminal of the battery 'I.. Therefore, depression of the button I5 with the :switchi closed will result in extinguishing the flashlight bulb 5, although one side of the battery will still be connected to the testing stud M.

In order to maintain the button I6 in a depressed condition, the disk portion I3 of the cap 8 provides a stud II carrying a latch arm I8, held on the stud -I'I by a nut I9. The arm `vI8 can be swung to engage the button I6 as shown in Fig. '5, `and by turning down on the nut I9, the latch arm I8 4will hold the button I5 4depressed Isurficiently to disengage the end portion I2a of the spring I2 from `the cap 8. Assuming that the Aswitch `(i -is closed, holding in of the button 'I6 vby the latch larm I8 will prevent illumination of the bulb 5, and the aslilight can then Abe used for a 'test by connecting the ends of the circuit or'idevice to be tested between the stud I4 and either the cap 8 or the shell I.

For convenience in making such a test, the stud I'4 'carries a terminal 2li held thereon by a nut v21. Should it be desired to test a plug type fuse, indicated in dotted lines kat F in Fig. 5, itis only necessary to apply the terminal 20 to the inside terminal of the fuse while holding the outside sleeve of the fuse in engagement with the cap 8. If the fuse is good, the bulb 5 will light, since the fuse itself lwill provide a current path `frcmone side of the battery -I, inner Aportion 12b of spring I 2stud I Il .and from thence through the fuse F to the cap 8 and the shell I through the `closed switch 5, bulb 5 back to the other side of the battery.

As previously pointed out, the device of the -present invention also provides means `for meastiring the approximate `resistance of an electrical circuit or -other device. To this end, the disk I3 of the cap 8 provides a third stud 22 that is insu- -lated from :the vcap at.23, with its inner end connected lby a lead 24 to one terminal of the `wi-nding Y25 of the .meter II. As best :shown in Fig. 4, the other .lead 2B of the winding 25 is connected :to Ythe testing :stud :I4 which carries the battery pnntafctsm'ing 12, so that ione :side of the meter winding '.24 is always .connected to one sideof the rba'ttery El, so longas the cap 8 remains on the shell i. For convenience in :utilizing the .meter 9 and .for testing purposes, the stud 22 carries a ter- :minal 2l held thereon by means cfa nut 2B.

Should it be desired to check vthe .operativeness .of a piece of electrical .equipment Iprovided with :a scoil, indicated in :dotted lines at C in Fig. 5, one flea-d from the coil C is connected to the terminal 21, while the other lead is :connected tothe leap 8 or shell iI. If the coil C under test is able 1lio-pass current, Vthe resulting energ-ization of the meter Winding 9 in series with the coil C `will `result .in `a Vdeflection `of the pointer 29 oi the meter. As shown in Fig. l5, the .scale 13|] `of the :meter 4is graduated ohms and volts, so that the deflection Vof the pointer 29 will give quite an accurate indication as to whether the resistance of the coil under test is high or low.

From the foregoing, it is apparent that by the present invention there is provided an improved electrical testing device in the form of a convenient attachment which may be readily mounted on a conventional portable flashlight after removal of its end cap. As previously pointed out, `my ydevice may be conveniently employed for testing electrical circuits or various other electrical devices under examination, such vas fuses, lamp bulbs, windings, and condensers. For convenience of the user, the disk portion I3 =of the cap 8 bears suitable markings adjacent the testing studs I4 and 22, as shown in Fig. 5.

For example, the stud I4 may be marked Ba-t. to indica-te that this stud is permanently connected to one terminal of the battery 1 through the 'contact s-pring I2. The stud 22 may be marked Meter to indicate that this stud is permanently fconnected to one terminal of the lwinding .25 of the meter I1.

While electrical devices may betested as previously described Iby establishing circuits through such devices from either the battery terminal 2E] .or the meter terminal 21andthecap B or shell I, the ethird stud Il carrying `the latch arm I 8 `may be used for :making connection to the shell. For lthis reason, the stud IFI is marked Shell and, :if desired, a testing :lead maybe connected to the stud il yby its nut 'I'.S, :as .indicated Vin dotted lines in Fig. 5.

In `actual use of. my improved device by .an electrician, laggreat many circuits and 'devices can be yquickly tested Yas to the ability nof the circuit or device to transmit current, as well fas its relative resistance. For example, a fuse ywhich appears to be unblowri lcan be A'quickly tested through -either terminal '20 or '21,. 'If the ifuse is unblown, the ashlight bulb k5 will `be illuminated when the fuse is applied as shown in Fig. .5. If, however, kthe same fuse when applied to meter terminal 21 4and `the shell l gives Ya Very .small deflection of the meter pointer, that would indicate a faulty connection in the fuse itself, by reason of the high indicated resistance; otherwise the resistfance would be verysmall. When testing a device such as a relay with a coil of relatively high resistance, connection of the coil between meter terminal `27I andthe shell will sho-w a small deflection 'of the pointed, even though testing of the vsame coil from the battery terminal 20 would not light the bul-b 5, due tothe same high resistance.

`I claim:

l. A ytesting device for attachment to a flashlight having anopen-ended casing of conducting material containing `azbattery, comprising, a cupshaped cap `providing a portion of conducting material adapted to be detachably secured over and 'to ybe electrically connected to the open end of the flashlight casing, a `resilient conducting member insulatingly carried within said cap and having one end portion thereof extending outwardly from said cap so as to be adapted for engaging one pole of the battery, the other end of said member being normally disposed in conta-ct with said cap, a manually operable push button mounted within `said cap and operable from the outside of said cap to break the normal connection between said cap and said resilient member, rst and second testing terminals each mounted upon the outer face of and insulated from said cap, Said first terminal being electrically connected to said resilientmember, a meter secured upon said cap, an electrical lead connect- 5 ing one side of said meter to said resilient member, and an electrical lead connecting the other side of said meter to said second terminal.

2. A testing device for attachment to a flashlight having an open-ended casing of conducting material containing a battery, comprising, a cupshaped cap providing a portion of conducting material adapted to be detachably secured over and to be electrically connected to the open end of the ilashlight casing, a resilient conducting member insulatingly carried Within said cap and having one end portion thereof extending out- Wal'dly from said cap so as to be adapted for engaging one pole of the battery, a manually operable switch mounted upon the outer face .of said cap for making and breaking an electrical circuit between said resilient member and said cap, rst and second testing terminals each mounted upon the outer face of and insulated from said cap, said first terminal being electrically connected to said Iresilient member, a cupshaped cover hingedly mounted upon said cap so as to be removably positioned over said terminals, a meter mounted within said cover, an electrical lead connecting one side of said meter to said resilient member and an electrical lead connecting the other side of said meter to said second terminal.

3. A testing device for attachment to a flashlight having an open-ended casing of conducting material containing a battery, comprising, a cupshaped cap providing a portion of conducting material adapted to be detachably secured over and to be electrically connected to the open end of the ilashlight casing, a resilient conducting mem- -ber insulatingly carried Within said cap and having one end portion thereof extending outwardly from said cap so as to be adapted for engaging one pole of the battery, the other end of said member being normally disposed in contact with said cap, a manually operable push button mounted within said cap and operable from the outside of said cap to break the normal connection between said cap and said resilient member, iirst and second testing terminals each mounted upon the outer face of and insulated from said cap, said first terminal being electrically connected to said resilient member, a third testing terminal mounted upon and -electrically connected with the outer face of said cap, a cupshaped cover hingedly mounted upon said cap so as to be removably positioned over said terminal, a meter mounted within said cover, an electrical lead connecting one side :of said meter to said resilient member, and an electrical lead connecting the other side of said meter to said second terminal.

GO-TTFRIED CARL ZACI-IAE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,528,709 Trimble Mar. 3, 1925 1,707,051 Colosoii Mar. 26, 1929 2,292,730 Zachae Aug. 11, 1942 OTHER REFERENCES Electrical World, August 8, 1925, pages 257-259. 

